The article presents a brief history of the two-stage conflict that began in February 2014 and continues to this day. By describing four key periods of the first stage of the conflict, we highlight the problems faced by the military health service during this time. The changes in how medical and sanitary losses were managed during the various phases of the first stage of operations laid the groundwork for a unified medical support system in Ukraine during the later stage of the conflict. Modifications of the combat medical support system, aligned with Western standards, significantly enhanced the effectiveness of medical services within the Ukrainian army. Based on the experience of combat participants, necessary logistical and organizational changes that could further improve the medical evacuation system were identified. The aim of this paper was to present the evolution of the treatment and evacuation system during the course of hostilities in Ukraine. The transformations within the Ukrainian army’s medical evacuation system during the armed conflict require detailed analysis, with the findings serving to guide the operations of the military health service of the Polish Armed Forces.